1. Field of the Invention
This invention relates to an electrical connector of the type having an insulating material forming an insulative housing enclosing both an electrical terminal and a portion of the conductor, such as a wire, to which the terminal is attached. More particularly, this invention relates to an electrical connector having means for retaining the terminal in the housing. Specifically, this invention relates to an electrical connector in which the conductor is first inserted through the insulative housing and the terminal is crimped to the terminal on one side of the housing after which the terminal is then pulled back into a cavity within the insulative housing.
2. Description of the Prior Art
One common cause of unsatisfactory electrical connections in harnesses or devices employing a plurality of terminals within individual insulative housings arises from the difficulty of retaining or securing terminals in position within the housing. These problems are especially aggravated because the failure of one out of a number of terminals in a single multicontact housing or in a harness containing a plurality of multicontact terminals has proven difficult to avoid. Thus, although numerous connectors have been devised having generally satisfactory terminal retention configurations, most connectors are still subject to the occasional failure. These failure can be especially troublesome to locate and to repair. The difficulty of assuring proper terminal retention within multicontact housing is aggravated when the connector is used in an environment in which it is subject to vibration. Thus, although the terminal may initially be properly positioned within the housing, vibration may result in disengagement of the terminal over time. These problems are especially significant in automotive wiring harnesses.
A number of configurations have been employed in an attempt to alleviate these problems. One such electrical connector which has exhibited generally satisfactory performance is that disclosed in U.S. Pat. No. 4,557,542. This connector employs a plurality of flexible latch arms having distal ends formed to engage surfaces on terminals inserted in the housing cavities. When crimp snap connectors of the type shown in this patent are inserted from the rear or wire receiving end of the housing, the resilient latch arms initially are cammed to flex outwardly to permit full insertion of the crimp snap terminals into the housing cavities. Upon complete insertion of the terminals into the cavities, the flexible latch arms snap back into position to engage appropriate stop surfaces on the terminal. This particular device employs a separate wedge bar which can be inserted from the front or mating surface adjacent the receptacle portion of the terminals. This wedge bar engages the flexible latch retaining arms in the housing to ensure that the wedge bar remains in its fully deflected position. These wedge bars serve to provide terminal position assurance since the wedge bars cannot be fully inserted into engagement with the flexible latch arms unless the terminals themselves are properly inserted.
One significant disadvantage of electrical connectors constructed in this manner is that the principal electrical housing must be formed of a material sufficiently resilient to permit the latch arms to flex during terminal insertion. These latch arms also constitute complex structures making the housing more difficult and expensive to manufacture.
The disadvantages of employing resilient latching housing members such as that shown in U.S. Pat. No. 4,557,542 with crimp snap terminals inserted from the rear of the housing have generally been outweighed by the terminal application disadvantages. With a rear entry crimp snap configuration, as represented by U.S. Pat. No. 4,557,542, individual terminals may be attached to individual wires prior to assembly within a housing. Terminal application equipment suitable for performing this function in a rapid automated manner is generally available.
An alternative to the crimp snap rear entry configuration represented by U.S. Pat. No. 4,557,542 is the insertion of conductors through a terminal housing prior to the attachment of the terminals to the ends of the conductors. After the terminals are attached, the terminals can then be pulled to seat by pulling the wires, causing the terminals to enter the insulative housings from the front mating face. U.S. Pat. No. 3,667,101 discloses a pull to seat configuration in which stamped and formed pin and socket terminals are pulled to seat within a housing. The socket contacts depicted in that patent, like mating pin, contacts, are cylindrical in configuration so that orientation of the individual terminals within a housing is not required. Securement of the terminals in the housing is achieved by engagement of protruding rearwardly directed retaining lances which engage shoulders within the insulating housing. Protruding stabilizing dimples and lances are used to stabilize these terminals within the housing.
Pin and socket terminals such as those used in the configuration of U.S. Pat. No. 3,667,101 are in many cases, inappropriate for the interconnection desired for a particular application. Many automotive connectors employ tab and receptacle terminals which, unlike pin and socket terminals, must be properly oriented within the housing. U.S. Pat. No. 4,346,959 discloses a tab and receptacle configuration. That pull to seat connector is intended for use with terminals which are applied to the conductors prior to assembly in the housing. The conductors are inserted into slots on the outer side of the terminal housings and the terminals are then pulled into cavities communicating with the exterior slots. To ensure alignment of receptacle terminals, that patent employs a protruding tab which is received within the exterior slot in the housing. Another tab and receptacle pull to seat connector is shown in U.S. Pat. No. 4,588,242. That patent, too, has exterior slots in the housing which define resilient latching fingers on the exterior of the housing. These resilient latching fingers are cammed out of the way when the terminals are pulled into the connector.
These prior art, pull to seat connectors, however, generally employ either resilient lances for securing, aligning or stabilizing the terminals, or the cavities of the connector housing are not closed on all sides. Protruding lances on crimp snap terminals can result in entanglement of the conductors prior to installation in a housing and resilient protruding lances, such as those normally used with crimp snap connectors, can be bent so that they do not function properly upon insertion into the housing. Resilient fingers on connector housings not only complicate the molding of the housing but, especially for small connectors, are subject to damage when handled. Connectors in which the terminals are exposed along the sides of the connector housing have not found significant acceptance and can be subject to shorting or contamination, since the terminal is not protected by a fully enclosed housing. The instant invention avoids these problems by using a pull to seat approach in which the main housing body is formed of a one-piece rigid housing which does not employ any flexible terminal securing members, either in the housing or on the terminal.